TUBE HUNTER VACUUM TUBE GEMS

THESE ARE THE SPECIFICS OF THE TUBE/TUBES FOR SALE


THESE ARE THE TUBE/TUBES FOR SALE: 


  MANUFACTURER:                           

  CBS

PRODUCTION CITY:                                 

   USA

TUBE TYPE:

    6BA4

DESIGNATION:                                          

   PREAMP

YEAR:

   1950s

MONTH:

   VARIES

DATE MATCH PAIR:

   SINGLE

SILK SCREEN CONDITION %:                

  100%

MICA:

   2 

PLATES:

   GREY OR BLACK

GM % VALUE:

   120% 

SINGLE/PAIR/QUAD/MULTI:

   SINGLE

GETTER:                                                      

    O GETTER

DATE CODE                                               

    VARIES

THIS TUBE 6AB4 IS THE EQUIVALENT OF 1/2 OR ONE TRIODE OF A 12AT7.

THIS IS NOT A SUB FOR A 12AT7

THIS IS A 7 PIN TUBE WITH ONE TRIODE. A 12AT7 IS A PIN TUBE WITH 2 TRIODES.

 THIS AUCTION IS FOR ONE TUBE!!!

NOS NIB

THIS IS A STOCK PHOTO. YOU WILL RECIEVE A NEW NOS NIB TUBE.

THIS TUBE WILL BE NEW. IT MAY NOT HAVE PERFECT SILKSCREEN OF A PERFECT BOX, BUT IT WILL BE NEW AS DETERMINED BY ME AND TESTING.


On my tester a B&K 747 tester:    Below 55 = BAD      55-65 = ?     65 -100 = Good     100-120+ = NOS  

 

   No automatic alt text available. 


I want to see you happy with your purchase. I will never sell a tube that is below standard??

I have sold many tubes here on Ebay, and all my customers have been completely satisfied. I will work with you in good faith if there are any problems, or if you are unsatisfied in any way.

I want your business now and in the future, so I assume you are the boss, and I am the employee.

All tubes are tested for shorts, continuity, and emissions.

I prefer PayPal.

ALL CUSTOMERS PLEASE READ ALL NOTES BEFORE BUYING FROM ME !!

1.  RETURNS: It is my highest desire that you are completely satisfied with your purchase from me. I will bend over backwards to make sure that you are a happy customer.

If anything you buy from me is less than satisfactory, message me BEFORE you either open a case or hit the ?item not as described? button.

Sound quality is tremendously SUBJECTIVE. For tubes returned for "noise" or "sound quality of any kind" you pay for the shipping we refund the purchase. We refund the price of the item NOT THE SHIPPING COST. If we sent the wrong tube we will of course pay for return shipping. For any tubes that are DOA we require that you send a us a picture of the shipping box to show us the damage. We test EVERY tube sent out and none should be DOA unless broken in shipping.

2.    PLEASE NOTE:  Tube silkscreen (lettering on the tubes) is VERY fragile. It can be wiped off and destroyed VERY easily. If you wipe off the silkscreen while handling the tube you diminish their value by up to 70%. DO NOT handle the tubes or hold them from the cylinder. ALWAYS hold them from the ENDS. If you are returning tubes and they are not in the same condition cosmetically I cannot give you a full refund. THIS IS VERY IMPORTANT.

3.  UNLESS YOU MAKE ARRANGEMENTS WITH US BEFORE YOU PURCHASE, YOU MUST PAY FOR ITEMS PURCHASED WITHIN 2 DAYS OR A CASE WILL BE OPENED FOR AN UNPAID ITEM!!!

4. TESTING: I test all tubes that I sell in one way or another, or I will state "untested". I have a B&K 747 tube tester. This is a mutual conductance tester. It give a percentage value of gm for the tube under test and checks for shorts and grid emissions. I also use a Tektronix curve tracer for testing triodes. I give a number of evaluations for tubes. One evaluation is a screen shot of the tube with a high voltage applied to the plate. This helps the buyer see the linearity of the tube in question at the highest voltage the tube will see in a real circuit. The Curve tracer steps the triode through 10 gate/grid voltages starting with -10 volts and going to 0 volts. The lines show how the tube conducts throughout that range. At 0 volt the tube is at max conduction and is the top line on the display. It is easy at that point to take where that top line intersects the plate voltage, find the milliamp level and compare it to the datasheet. I give those numbers for you in the "Item condition box". To further help the buyer I also include the "Design values", for gm and ma readings in the table. This can then be compared to other tube sellers using inferior test methods such as Hickok,  Amplitrex, and other testers. The Tektronix curve tracer gives values within 3% of the actual value. The very best portable testers only can approach 10% accuracy.

5.    Please note: The numbers given for gm are what I see on my tester. I DO NOT guarantee that you will see those numbers on your tester. I only guarantee that these tubes will test good, with no shorts, or gas, on a decent calibrated tester. I don't guarantee or imply a

inkFrog